Appendectomy and the clinical course of ulcerative colitis: a retrospective cohort study and a nested case-control study from Korea

Appendiceal periappendicitis and ulcerative colitis: Relationship and research advances

The prevalence of ulcerative colitis (UC) has been increasing in China, reaching about 11.6 per 100000. The diagnostic process for this disease is extremely lengthy and complex, significantly impacting the patient's health. UC typically starts in the rectum and sigmoid colon, and when patients with distal colitis also present with appendiceal periappendicitis, this condition is considered a "skip lesion" of UC. This phenomenon may be related to the appendix's role as an immune organ and its immunological connection to the pathogenesis of UC. Appendiceal periappendicitis combined with rectal inflammation can facilitate the diagnosis of UC. However, there is still no consensus on the pathogenesis, treatment prognosis, and clinical significance of appendiceal periappendicitis. This paper reviews the recent literature and provides a comprehensive analysis of appendiceal periapp-endicitis.

Appendectomy and Risk of Advanced Colorectal Neoplasia in Inflammatory Bowel Disease: A Nationwide Population-based Cohort Study

BACKGROUND

The aim of this study was to examine the association between appendectomy and advanced colorectal neoplasia (aCRN) in patients with inflammatory bowel disease (IBD).

METHODS

Inflammatory bowel disease patients diagnosed in Denmark in the period 1977 to 2017 were identified from the Danish National Patient Registry. Inflammatory bowel disease patients who underwent appendectomy were matched with up to 10 IBD patients without appendectomy and followed until aCRN, death, or emigration. Absolute risks of aCRN were calculated, treating death and bowel resections as competing risks. Stratified Cox regression was used to calculate adjusted hazard ratios (aHRs) of aCRN, comparing IBD patients with appendectomy to IBD patients without appendectomy.

RESULTS

We identified 3789 IBD patients with appendectomy and 37 676 IBD patients without appendectomy. A total of 573 patients (1.4%) developed aCRN, with an absolute risk of aCRN at 20 years of 4.9% (95% confidence interval [CI], 2.9%-7.7%) for ulcerative colitis (UC) patients with appendectomy after UC diagnosis compared with 2.8% (95% CI, 2.3%-3.3%) for UC patients without appendectomy. Appendectomy after UC was associated with an increased rate of aCRN 5 to 10 years (aHR, 2.5; 95% CI, 1.1-5.5) and 10 to 20 years after appendectomy (aHR, 2.3; 95% CI, 1.0-5.5). Appendectomy prior to UC diagnosis was not associated with an increased rate of aCRN, and Crohn's disease was not associated with the rate of aCRN, regardless of timing or histological diagnosis of the appendix specimen.

CONCLUSIONS

Although appendectomy may have a positive effect on the clinical course of UC, our study suggests that this may come at the expense of a higher risk of aCRN.

The Role of Appendicectomy in Ulcerative Colitis: Systematic Review and Meta-Analysis

BACKGROUND

This updated systematic review and meta-analysis investigates the putative role of the appendix in ulcerative colitis as a therapeutic target.

METHODS

Ovid Medline, Embase, PubMed and CENTRAL were searched with MeSH terms ("appendectomy" OR "appendicitis" OR "appendix") AND ("colitis, ulcerative") through October 2020, producing 1469 references. Thirty studies, including 118 733 patients, were included for qualitative synthesis and 11 for quantitative synthesis. Subgroup analysis was performed on timing of appendicectomy. Results are expressed as odds ratio (OR) with 95% confidence intervals (CIs).

RESULTS

Appendicectomy before UC diagnosis reduces the risk of future colectomy (OR, 0.76; 95% CI, 0.65-0.89; I2 = 5%; P = .0009). Corresponding increased risk of colorectal cancer and high-grade dysplasia are identified (OR, 2.27; 95% CI, 1.11-4.66; P = .02). Significance is lost when appendicectomy is performed after disease onset. Appendicectomy does not affect hospital admission rates (OR, 0.87; 95% CI, 0.68-1.12; I2 = 93%; P = .27), steroid use (OR, 1.08; 95% CI, 0.78-1.49; I2 = 36%; P = .64), immunomodulator use (OR, 1.04; 95% CI, 0.76-1.42; I2 = 19%; P = .79), or biological therapy use (OR, 0.76; 95% CI, 0.44-1.30; I2 = 0%; P = .32). Disease extent and risk of proximal progression are unaffected by appendicectomy. The majority (71% to 100%) of patients with refractory UC avoid colectomy following therapeutic appendicectomy at 3-year follow-up.

CONCLUSIONS

Prior appendicectomy reduces risk of future colectomy. A reciprocal increased risk of CRC/HGD may be due to prolonged exposure to subclinical colonic inflammation. The results warrant further research, as consideration may be put toward incorporating a history of appendicectomy into IBD surveillance guidelines. A potential role for therapeutic appendicectomy in refractory left-sided UC is also identified.

Appendix and Ulcerative Colitis: a Key to Explaining the Pathogenesis and Directing Novel Therapies?

The vermiform appendix is generally considered a redundant organ, but recent evidence suggests that the appendix could contribute to the pathogenesis of inflammatory bowel diseases, in particular ulcerative colitis (UC), and may even have a therapeutic role; however, mechanisms of the appendix involvement remain unclear. Here, we highlight current evidence on the link between the appendix and UC and consider plausible therapeutic implications. A literature search was conducted using PubMed and PubMed Central from inception to Nov 2021 using the terms "Appendix", "UC", "Appendix & UC," "Appendectomy", and "Peri-appendicular patch," including only articles published in English. Reference lists from the selected studies were manually searched and reviewed to gather additional related reports. Inflammation around the appendix ("peri-appendicular patch") has been frequently observed in UC patients without other cecal involvement, and this inflammation can even precede the onset of UC. Epidemiologic studies propose that appendectomy reduces the risk of developing UC or even the risk of flare after UC is diagnosed, although this remains controversial. We reviewed studies showing altered host-microbe interactions in the appendix in UC, which suggest that the appendix could act as a priming site for disease via alterations in the immune response and changes in microbiota carried distally to the colon. In summary, recent literature suggests a possible role for microbes and immune cells within the appendix; however, the role of the appendix in the pathogenesis of UC remains unclear. Further research could clarify the therapeutic potential related to this organ.

Endoscopic retrograde appendicitis therapy in the management of chronic fecalith appendicitis in a patient with ulcerative colitis: The first human case report

To assess the effectiveness of endoscopic retrograde appendicitis therapy (ERAT) as a new technique and method for chronic fecalith appendicitis complicated by active ulcerative colitis. A 46-year-old male patient was admitted with right iliac fossa pain, tenderness, and raised inflammatory markers. A computed tomography (CT) scan of his abdomen confirmed a dilated appendix, which is considered chronic fecalith appendicitis combined with active ulcerative colitis. He was treated with an endoscopic retrograde appendicitis therapy procedure. The patient recovered well after the ERAT procedure and was discharged from the hospital in two days. On follow-up one year later, there was no recurrence of pain in his abdomen. In conclusion, ERAT could be seen as a different approach and be favored as a safer and more effective option in treating UC patients with appendicitis, especially those who are later in the course of the disease. Because of the ERAT procedure, such cases can avoid surgery and surgery-related complications. More research and issues must be addressed to demonstrate the efficacy and effectiveness of ERAT in appendicitis combined with UC.

The Risk of Colectomy and Colorectal Cancer After Appendectomy in Patients With Ulcerative Colitis: A Systematic Review and Meta-analysis

BACKGROUND

Appendectomy decreases the risk of developing ulcerative colitis [UC], and is suggested to have a beneficial effect on the clinical course of established UC. However, recent studies showed no significantly decreased colectomy rate, and moreover an apparently increased risk of colorectal cancer [CRC]. We aimed to investigate the suggested correlation in a meta-analysis and to analyse possible confounding factors.

METHODS

A systematic review and meta-analysis were performed using MEDLINE, EMBASE, and the Cochrane Library. Data from studies describing the influence of appendectomy on colectomy and CRC were extracted from published reports. Exclusion criteria were patients aged <18 years, non-UC, and animal studies.

RESULTS

From 891 studies, 13 studies evaluating 73323 UC patients [appendectomy n = 2859] were included. All studies, except one, were rated as poor quality. Overall, colectomy rate in appendectomised and non-appendectomised patients was not significantly different (odds ratio [OR] 1.25, 95% confidence interval [CI] 0.88-1.77, I2 = 53%). The proportion of colectomies undertaken for CRC or high-grade dysplasia [HGD] was significantly higher after appendectomy [OR 2.85, 95% CI 1.40-5.78, I2 = 32%], with 50% of the colectomies indicated for CRC/HGD compared with 9.4% in non-appendectomised patients. Possible additional confounding factors were a longer UC disease duration, less medication use, and a higher prevalence of primary sclerosing cholangitis [PSC] in appendectomised patients.

CONCLUSIONS

Appendectomy in established UC is associated with apparently higher rates of subsequent CRC/HGD, but this appears to be due to inequalities in at-risk exposure between groups, presumably secondary to positive clinical effects of appendectomy on disease symptoms. This finding emphasises the importance of regular endoscopic surveillance in this patient group.

Effects of Appendectomy on the Onset and Course of Ulcerative Colitis in Chinese Patients

Background

Previous epidemiological studies have suggested that appendectomy may be a protective factor against the development of ulcerative colitis (UC). However, the results of these studies were inconsistent, with rare studies in Chinese populations.

Aim

This study examined the associations between appendectomy performed before UC diagnosis and the occurrence and clinical course of UC in Chinese patients.

Methods

A case control study was conducted to compare the rate of appendectomy between UC patients and controls matched for age and sex at two Chinese hospitals. Clinical course of UC was compared between UC patients who underwent appendectomies before UC diagnosis and who did not.

Results

402 UC patients and 402 controls were included. The percentage of appendectomy performed before UC diagnosis in UC patients did not differ significantly from controls (2.74% vs 3.98%, P = 0.442). Subgroup analysis on the basis of localization of UC patients did not find significant difference from controls. The extent of disease involvement in UC patients who underwent appendectomy was smaller than patients who did not (P = 0.009). Appendectomy was found to be significantly related to the location of the disease independent of smoking status in multivariate analysis (P < 0.001). Appendectomy did not influence severity of disease and need for immunosuppressive treatment or colectomy.

Conclusion

We did not find a significant negative association between appendectomy and the UC occurrence in Chinese patients. Appendectomy performed before UC diagnosis may reduce the extent of UC involvement.

Long-Term Complications of Appendectomy: A Systematic Review

BACKGROUND AND AIMS

Appendectomy is a common surgical procedure, but no overview of the long-term consequences exists. Our aim was to systematically review the long-term complications of appendectomy for acute appendicitis.

MATERIALS AND METHODS

This systematic review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A protocol was registered on PROSPERO (CRD42017064662). The databases PubMed and EMBASE were searched for original reports on appendectomy with n ≥ 500 and follow-up >30 days. The surgical outcomes were ileus and incisional hernia; other outcomes were inflammatory bowel disease, cancer, fertility, and mortality.

RESULTS

We included 37 studies. The pooled estimate of the ileus prevalence was 1.0% over a follow-up period of 4.6 (range, 0.5-15) years. Regarding incisional hernia, we found a pooled estimate of 0.7% prevalence within a follow-up period of 6.5 (range, 1.9-10) years. Ulcerative colitis had a pooled estimate of 0.15% prevalence in the appendectomy group and 0.19% in controls. The opposite pattern was found regarding Crohn's disease with a pooled estimate of 0.20% prevalence in the appendectomy group and 0.12% in controls. No clear pattern was found regarding most of the examined cancers in appendectomy groups compared with background populations. Pregnancy rates increased after appendicitis compared with controls in most studies. Mortality was low after appendectomy.

CONCLUSION

Appendectomy had a low prevalence of long-term surgical complications. We did not find any significant other long-term complications, though the prevalence of Crohn's disease was higher and the prevalence of ulcerative colitis was lower after appendectomy than in controls. Appendectomy did not impair fertility.

Meta-analysis of the association between appendiceal orifice inflammation and appendectomy and ulcerative colitis

OBJECTIVE

This study aimed to investigate the relationship between appendiceal orifice inflammation (AOI) and appendectomy and ulcerative colitis (UC) by a meta-analysis.

METHODS

Databases were thoroughly searched for studies on AOI and UC up to January 2016. Three comparisons were performed: a) whether the previous appendectomy was a risk factor of UC; b) influence of appendectomy on UC courses; c) influence of AOI on UC severity. Odds ratios (ORs) and 95% confidence intervals (CIs) were the effects sizes. The merging of results and publication bias assessment were performed by using RevMan 5.3. Sensitivity analysis was conducted using Stata 12.0.

RESULTS

Nineteen studies were selected in the present study. Results of comparison I showed that appendectomy was a protective factor of UC (OR = 0.44; 95% CI [0.30, 0.64]). Comparison II indicated appendectomy had no significant influence in the courses of UC (proctitis: OR = 1.03, 95% CI [0.74, 1.42]; left-sided colitis: OR = 1.01, 95% CI [0.73, 1.39]; pancolitis: OR = 0.92, 95% CI [0.59, 1.43]; colectomy: OR = 1.38, 95% CI [0.62, 3.04]). Comparison III indicated UC combined with AOI did not affect the courses of UC (proctitis: OR = 1.15, 95% CI [0.67, 1.98]; left-sided colitis: OR = 1.14, 95% CI [0.24, 5.42]; colectomy: OR = 0.36, 95% CI [0.10, 1.23]). Sensitivity analysis confirmed the robust of the results in the present study.

CONCLUSION

In conclusion, this meta-analysis indicated appendectomy can reduce the risk of UC. But appendectomy or AOI had no influence on the severity of the disease and the effect of surgical treatment.

Appendectomy and the Risk of Colectomy in Ulcerative Colitis: A National Cohort Study

OBJECTIVES

Ulcerative colitis (UC) is a chronic inflammatory disease usually responding well to anti-inflammatory drugs but many patients will still need colectomy. Appendectomy is associated with a lower risk of later developing UC. We aimed to assess the longitudinal relationship between appendectomy, appendicitis, and disease course in UC patients.

METHODS

A national cohort of UC patients with a diagnosis in 1964-2010 was identified from the Swedish National Patient Register that also provided information regarding appendicitis and/or appendectomy before or after the UC diagnosis. The risk for colectomy and UC-related hospital admissions was evaluated.

RESULTS

Among 63,711 UC patients, 2,143 had appendectomy and 7,690 underwent colectomy. Appendectomy for appendicitis before 20 years of age and for non-appendicitis at all ages before UC diagnosis was associated with a lower risk of colectomy (hazard ratio (HR) 0.44, 0.27-0.72 and HR 0.62, 0.43-0.90, respectively), and fewer hospital admissions (incidence rate ratio (IRR) 0.68, 95% confidence interval (CI) 0.64-0.73 and IRR 0.54, 0.47-0.63, respectively). Appendectomy for appendicitis after the UC diagnosis was associated with a higher risk of colectomy (HR 1.56, 1.20-2.03), whereas no such association was found for other pathology (HR 1.40, 0.79-2.47).

CONCLUSIONS

Appendectomy early in life and before developing UC is associated with a lower risk of colectomy as well as UC-related hospital admissions. Appendectomy for appendicitis after established UC appears associated with a worse disease course, with an increased rate of subsequent colectomy.

Appendectomy does not decrease the risk of future colectomy in UC: results from a large cohort and meta-analysis

OBJECTIVES

Early appendectomy is inversely associated with the development of UC. However, the impact of appendectomy on the clinical course of UC is controversial, generally favouring a milder disease course. We aim to describe the effect appendectomy has on the disease course of UC with focus on the timing of appendectomy in relation to UC diagnosis.

DESIGN

Using the National Institute of Diabetes and Digestive and Kidney Diseases Inflammatory Bowel Disease Genetics Consortium database of patients with UC, the risk of colectomy was compared between patients who did and did not undergo appendectomy. In addition, we performed a meta-analysis of studies that examined the association between appendectomy and colectomy.

RESULTS

2980 patients with UC were initially included. 111 (4.4%) patients with UC had an appendectomy; of which 63 were performed prior to UC diagnosis and 48 after diagnosis. In multivariable analysis, appendectomy performed at any time was an independent risk factor for colectomy (OR 1.9, 95% CI 1.1 to 3.1), with appendectomy performed after UC diagnosis most strongly associated with colectomy (OR 2.2, 95% CI 1.1 to 4.5). An updated meta-analysis showed appendectomy performed either prior to or after UC diagnosis had no effect on colectomy rates.

CONCLUSIONS

Appendectomy performed at any time in relation to UC diagnosis was not associated with a decrease in severity of disease. In fact, appendectomy after UC diagnosis may be associated with a higher risk of colectomy. These findings question the proposed use of appendectomy as treatment for UC.

Huangqin-Tang and Ingredients in Modulating the Pathogenesis of Ulcerative Colitis

Ulcerative colitis (UC) is the most common inflammatory bowel disease worldwide. Current therapies in UC cause limitations, and herb medicine provides an important choice for UC treatment. Huangqin-Tang (HQT) is a well-known classical traditional Chinese herbal formula and has been used in China for thousands of years. A large number of pharmacological studies demonstrated HQT and its ingredients to be effective in treating UC. Though the therapeutic effect has been evaluated, comprehensive up-to-date reviews in this field are not yet available. Here we aim to review our current understanding of HQT and its ingredients in treating UC and how the agents modulate the main pathogenesis of the disease, including the intestinal environment, immune imbalance, inflammatory pathways, and oxidative stress. The summary on this issue may provide better understanding of HQT and its ingredients in treating UC and possibly help in promoting its clinical application.

The Link between the Appendix and Ulcerative Colitis: Clinical Relevance and Potential Immunological Mechanisms

The human appendix has long been considered as a vestigial organ, an organ that has lost its function during evolution. In recent years, however, reports have emerged that link the appendix to numerous immunological functions in humans. Evidence has been presented for an important role of the appendix in maintaining intestinal health. This theory suggests that the appendix may be a reservoir or 'safe house' from which the commensal gut flora can rapidly be reestablished if it is eradicated from the colon. However, the appendix may also have a role in the development of inflammatory bowel disease (IBD). Several large epidemiological cohort studies have demonstrated the preventive effect of appendectomy on the development of ulcerative colitis, a finding that has been confirmed in murine colitis models. In addition, current studies are examining the possible therapeutic effect of an appendectomy to modulate disease course in patients with ulcerative colitis. This literature review assesses the current knowledge about the clinical and immunological aspects of the vermiform appendix in IBD and suggests that the idea of the appendix as a vestigial remnant should be discarded.